Internet topology has been studied both on AS
[1]}, [2]}
and router level
[3]}, [4]}, [5]}, [6]}. On both level the Internet can
be modeled as a graph from graph theory. One of the most fundamental
quantities used for describing the structure of a graph is the degree sequence,
which is to say the number of the neighbors of nodes. It has been found that
the distribution of the degree sequence follows a power law \(P(k)\sim k^{-\delta }\)  on both level. The appearance of a power law indicates the
scale-free nature of a particular object, so a graph the degree distribution of
which follows power law is called scale-free graph. Note that in recent
years the statistical properties of other scale-free networks have been
investigated by the physics community as well
[7]}, [8]}, [9]}, [10]}. Examples of
such networks vary from social interconnections and scientific collaborations
[11]} to the www [12]}.
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